The use of nondestructive testing methods for the condition assessment of concrete bridge girders

Abstract

There are over 594,000 publicly controlled bridges in the United States. Concrete and pre-stressed concrete bridges account for nearly 50% of the bridges in the US inventory. This proportion is increasing each year, as new bridges tend to be constructed of concrete. This trend makes it vital for engineers to be able to accurately assess the condition of concrete for maintenance and repair decisions. The use of nondestructive testing methods can help reduce the backlog of deficient bridges in two ways. First, these techniques will allow inspectors to get a more accurate view of the condition of a bridge. The second way by which NDT can help is by allowing inspectors to locate damage earlier. This thesis is an attempt to capture the most current ideas for a very specific application of NDT: determining the condition of reinforced concrete bridges overall and bridge girders, in particular. To this end, attention is given to why NDT is needed and what aspects of concrete condition can be addressed with NDT. Some NDT methodologies that are, or may soon be, promising for concrete applications are discussed. Case studies are presented to demonstrate how NDT can be applied to concrete bridge girders and proposals are made for future areas of study and development.